Boden, I., Skinner, E., Browning, L., Reeve, J., Anderson, L., Hill, C., … Denehy, L. (2018). Preoperative physiotherapy for the prevention of respiratory complications after upper abdominal surgery: pragmatic, double blinded, multicentre randomised controlled trial. BMJ (Clinical Research Ed.), 360, j5916. Retrieved from http://www.bmj.com/cgi/pmidlookup?view=long&pmid=29367198 (Original work published 2018)